Sir Alex Ferguson is surprised that Mark Hughes has made it as a manager. Photograph: Mike Egerton/EMPICS Sport

Sir Alex Ferguson has revealed that he "never in a million years" expected Mark Hughes to become a manager when the former Wales forward played under him at Manchester United.

Hughes has gone on to successfully manage his country and Blackburn Rovers before taking his current job with Manchester City, who will play Ferguson's United in the semi-finals of the Carling Cup next month.

"It's difficult to assess that because you don't know what ambitions the players have," Ferguson told Inside United magazine. "Currently we've got [Ryan] Giggs, [Paul] Scholes and [Gary] Neville taking their coaching badges. That's great and I encourage them to do that because it gives them a platform if they want to stay in the game.

"It can be difficult to pinpoint who would make it as a manager. For instance, nobody here thought Mark Hughes would become a manager, never in a million years, and we all thought Bryan Robson was a certainty to be a top manager."